#include <clutter/clutter.h>
#include <stdlib.h>

ClutterActor *rect = NULL;

/* This must return a value between 0 and 1.0
 *
 * This will be called as many times per seconds as specified in our call to clutter_timeline_new().
 *
 */
gdouble
on_alpha (ClutterAlpha *alpha, gpointer data)
{
  /* Get the position in the timeline, 
   *  so we can base our value upon it:
   */
  ClutterTimeline *timeline = clutter_alpha_get_timeline (alpha);
  return clutter_timeline_get_progress (timeline);
}


int main(int argc, char *argv[])
{
  ClutterColor stage_color = { 0x00, 0x00, 0x00, 0xff };
  ClutterColor rect_color = { 0xff, 0xff, 0xff, 0x99 };

  clutter_init (&argc, &argv);

  /* Get the stage and set its size and color: */
  ClutterActor *stage = clutter_stage_get_default ();
  clutter_actor_set_size (stage, 200, 200);
  clutter_stage_set_color (CLUTTER_STAGE (stage), &stage_color);

  /* Add a rectangle to the stage: */
  rect = clutter_rectangle_new_with_color (&rect_color);
  clutter_actor_set_size (rect, 40, 40);
  clutter_actor_set_position (rect, 10, 10);
  clutter_container_add_actor (CLUTTER_CONTAINER (stage), rect);
  clutter_actor_show (rect);

  /* Show the stage: */
  clutter_actor_show (stage);

  ClutterTimeline *timeline =  clutter_timeline_new(5000 /* milliseconds */);
  clutter_timeline_set_loop(timeline, TRUE); 
  clutter_timeline_start(timeline);

  /* Create a clutter alpha for the animation */
  ClutterAlpha* alpha = clutter_alpha_new_with_func (timeline, &on_alpha, NULL, NULL);

  /* Create an animation to change the properties */
  ClutterAnimation* animation = 
    clutter_actor_animate_with_alpha (rect, alpha, 
      "x", 150.0, 
      "y", 150.0,
      "opacity", 0,
      NULL);

  g_object_unref (animation);
  g_object_unref (timeline);

  /* Start the main loop, so we can respond to events: */
  clutter_main ();

  return EXIT_SUCCESS;
}

